In order to perform this type of processing operation, straight and continuous machines are currently known, for example of the type described in U.S. Pat. No. 4,426,825, said machines also packaging individually rolls of paper with a sheet of packaging material which is wound tightly around the roll itself and the edges of which are then folded over and sealed together. These machines have large dimensions in plan view and this condition may restrict the use thereof.
The object of the invention is to provide an automatic machine operating in a continuous rapid cycle, for the individual packaging of rolls of paper of varying size or other products, using a preferably heat-sealable packaging material, which has small dimensions in plan view, has a relatively simple design and is easily adjustable for adaptation to the varying size of the rolls to be packaged and which handles the rolls themselves delicately. It is stated by way of a premise that below the simplified term of "roll" will be used to indicate the roll of paper or other suitable product which can be packaged by the machine in question. The simplified term of "sheet" will also be used to indicate the sheet of material for packaging the roll.
The machine according to the invention comprises:
a) a main carousel with a horizontal axis, provided with angularly equidistant seats which are open outwards, have adjustable dimensions and are suitable for each containing a roll arranged with its axis parallel to that of the carousel itself. Each seat is provided at the front with gripper means for retaining the front transverse edge of the packaging sheet and is provided at the rear with a folding device normally in a retracted position which, upon actuation, closes the seat laterally so as to fold onto the roll the rear transverse edge of the sheet still retained by the gripper means; PA1 b) adjustable means which in synchronism supply to the gripper means of each seat of the main carousel, a packaging sheet which has dimensions suited to the size of the roll to be packaged, obtained preferably from a reel of packaging material and which is arranged on the seat. The width and length of each sheet are suitably greater than the generatrix and diameter of the roll, respectively; PA1 c) adjustable means for orienting the rolls with the axis transverse with respect to the feeding direction and parallel to the axis of the main carousel, into the seats of which the rolls themselves are individually inserted by a first auxiliary carousel with a horizontal axis parallel to that of the main carousel, with which it rotates in synchronism. The first auxiliary carousel is located downstream of the sheet supplying means and is provided with angularly equidistant grippers which are adjustable according to the variation in size of the rolls and which each grip the ends of a roll supplied by the supply means so as to subject the roll itself to a stress in the axial direction in which the roll itself has the greatest resistance owing to its cylindrical shape and the presence of the cardboard core. The first auxiliary carousel inserts the rolls by means of translation into each seat of the main carousel and, during this step, each roll is partially wrapped with the wrapping sheet which is retained on the seat itself by the associated front gripper; PA1 d) adjustable means which, following the intervention of the rear folding device of each seat of the main carousel, which folds onto the roll the rear transverse edge of the sheet and following opening of the front gripper of the same seat, fold onto the roll itself the front transverse edge of the sheet which was first retained by the gripper, while in synchronism the said rear folding device returns into the rest position so as to allow the transverse edges of the sheet to be arranged on top of one another; PA1 e) any means of the carousel type, with a horizontal axis, arranged downstream of the preceding means, so as to seal together the transverse overlapped edges of the packaging sheet; PA1 f) means which may be adjustable, for folding onto the ends of each roll located in the seats of the main carousel, the section of the packaging sheet which projects from the same ends of the roll; PA1 g) a second auxiliary carousel, which has a horizontal axis parallel to that of the other carousels and is similar to the first auxiliary carousel supplying the rolls and which extracts from the main carousel the packaged rolls, holding them by their ends so as to keep the closed end edges of the packaging arranged on top of one another and this carousel being designed so as to transfer the packaged rolls to means arranged downstream; PA1 h) conveying means which are adjustable according to the variation in size of the rolls and which grip the ends of the packaged rolls unloaded by the second auxiliary carousel and which if necessary complete closing of the ends of the packaging and which if necessary seal the overlapped end edges of the wrapping of the rolls and which convey away the rolls, for example towards packing means.
According to a preferred embodiment of the invention, the seats of the main carousel are adaptable to the varying size of the rolls, with self-centering adjustment and with a variation in their depth, so that the position of the rolls themselves towards the outside and consequently with respect to the gripper of the packaging sheet and the folding device associated with each seat and with respect to the station sealing the transverse edges of the packaging sheet. The grippers of the first and second auxiliary carousel, as well as the means supplying the packaging sheet and also the means for folding over the ends portions of the packaging sheet, and finally the means for sealing these ends of the packages, are adaptable to the varying size of the rolls, with self-centring adjustments with respect to the ideal vertical center line of the main carousel.